Effects of an agri-environment scheme on bumblebee reproduction at local and landscape scales

Carvell, Claire, Bourke, Andrew F. G., Osborne, Juliet L. and Heard, Matthew S. (2015) Effects of an agri-environment scheme on bumblebee reproduction at local and landscape scales. Basic and Applied Ecology, 16 (6). pp. 519-530.

[img] Microsoft Word (Carvell_manuscript_BAAE_030814) - Submitted Version
Download (462kB)

    Abstract

    Agri-environment schemes (AES) have been implemented across Europe, aiming to mitigate effects of habitat loss in agro-ecosystems for a range of declining species. These include pollinating insects such as bumblebees, for which positive effects of AES on abundance and species richness have been shown. However, there is a lack of evidence for effects of AES on reproduction of target species, at either local or landscape scales. We conducted a large-scale study across landscapes exhibiting a gradient of agricultural intensity to investigate the effects of a targeted flower mixture, sown in patches of three different sizes, on an index of the total biomass of bumblebee sexuals (males and queens) on replicated transects within each landscape. We used this index (MQ) as a measure of bumblebee reproduction. After controlling for floral density on transects, we found that MQ was significantly higher on sown flower patches than on conventionally managed control patches at local scales throughout the three-year study. While sown flower patches did not significantly increase MQ in surrounding landscapes, MQ was higher in landscapes surrounding larger (1 ha) than smaller (0.25 ha) sown patches. Our results suggest that, while responses of different bee species may vary depending on the plant species sown, targeted flower mixtures can enhance bumblebee reproduction by providing locally attractive forage resources to bumblebees of all castes and sexes from nests within foraging distance. If established at large enough scales, sown flower patches may lead to a detectable spill-over of reproductives into surrounding landscapes. Furthermore, effects of sown patches on MQ were moderated by landscape context, the strongest positive responses being detected at sites with high proportions of arable land. This supports previous findings that AES can deliver greater net benefits for pollinators in more intensively farmed landscapes.

    Item Type: Article
    Uncontrolled Keywords: bombus,seed mixture,floral density,pollinators,sexual biomass,foraging,landscape scale
    Faculty \ School: Faculty of Science > School of Biological Sciences
    Depositing User: Pure Connector
    Date Deposited: 21 Sep 2015 17:44
    Last Modified: 20 Nov 2018 11:31
    URI: https://ueaeprints.uea.ac.uk/id/eprint/54480
    DOI: 10.1016/j.baae.2015.05.006

    Actions (login required)

    View Item